Perfect and Revenge

I have downloaded the copies of Perfect and Revenge that are on this site. I noticed that out of 306 levels each, Perfect only contains 115 levels and Revenge contains only 292 levels.

I understand this site's position on "duplicate" levels, but this severely breaks up sets that were not intended to be broken up. In addition, I have already found "duplicates" in the Perfect and Revenge files of other levels in other files.

This leads me to believe that the "algorithm" for determining duplicates is actually just a list of "known duplicates" and not really an algorithm for searching out supposed duplicates.

This in itself makes the "duplicate" idea a farce. In addition, it is apparent to me that Thinking Rabbit did not consider these puzzles to be "duplicate", as they included them in more than one collection, with each version being altered in some manner to distinguish it from the others.

This can be defined as follows: Up is NOT down, left is NOT right. Just because a piece of software allows you to flip a puzzle around in order to make a different solution work does not make the puzzle a duplicate. Any time you have to alter the orientation of a puzzle you are changing it. Again, up is NOT down, left is NOT right. To get a grasp of what I am saying, try pasting the solution to Original #1 to a vertically flipped copy of that puzzle. Every Sokoban engine I know of will tell you that the solution is not valid for that puzzle.

Now that I have gotten that rant out of my system I will continue with my request. I do not expect that this site will change its position on duplicates, so I'm not asking for that. What I do want is a copy of Perfect and a copy of Revenge with all 306 levels in each set. Can anyone here point me to links for such copies?

This sites definition of a duplicate level is definitely not a list of known duplicates. The exact algorithm is described here.

I realize that I may have been harsh. I meant no harm, so if I have offended you I apologize. The algorithm is interesting. However, it does nothing to dissuade any of my other comments concerning duplicates.

If a level is rotated or mirrored, the solution can easily be rotated or mirrored. The challenge of a rotated level is exactly the same as for the original level, in my opinion.

As I do not wish to argue over something that we will obviously never agree on, I will just let it go here.

I am still wanting to know if there is a copy of the complete perfect and revenge levels anywhere that I can get a copy of. It is difficult to make comparisons when you have nothing to compare with.

In thinking about it, I have found one final argument concerning duplicates (specifically about their removal from sets) that I wish to make. I am not requiring this to be discussed or implemented. I provide it solely as food for thought.

I understand that this site is keeping a record of how many puzzles a user has solved, and that it is redundant to include solutions of duplicates since the user can simply paste the solution into the duplicate puzzle and it will be counted as solved. It does make sense to not count those puzzle's solutions when keeping track of unique solutions. However, removing puzzles from collections is not the only way to deal with this issue.

By removing the puzzles from the collection, you are telling the end-user that they have no choice but to accept your version of the collection. If your version of the collection is all that is available, you have further told the creator of that collection that they have no choice about which puzzles they can include in their collection. In addition, you are making it difficult (if not impossible) for those who are doing comparative research to be able to perform that research, especially if the collections they are studying are only found on this site. Basically, you are telling others what they can and cannot do, or have. I don't know about you, but I don't like someone else telling me what I can and cannot do or have when it is not their authority to do so.

If you use the argument, as in the case of the Perfect and Revenge collections, that the collections have not been granted permission for distribution by their owners as a reason for their incompleteness, then I would have to counter with the argument that by that reasoning you should not have Original, Boxxle 1 or 2, Perfect or Revenge on this site in any form at all, much less in a manipulated form.

I should be allowed my right to choose whether or not I want to play a given puzzle. If a collection is complete, and contains puzzles also found in other collections, I can choose to skip over those puzzles if I wish, or I can choose to play them if I so desire. If the collection is incomplete I am being denied that choice.

As for keeping track of solutions, if it is so simple to determine which puzzles are duplicates (by using your matching algorithm), then do so and add a field in your database that flags those puzzles as duplicates so that the counting algorithm skips over them in its counts.

Doing it that way allows the end-user to have the choice of which puzzles in which collections that they wish to play, and allows you control over which solutions are counted on this site. Making this change might also reduce the amount of coding required to perform all of these operations.

It's obvious that WayneCa is just not happy about not able to download the full set of Think Rabbit level sets. He's not happy about levels being removed, not really about levels being identified as identical.

For levels being identified as identical, there's nothing wrong with it.
If you must say something about it, it's that the current algorithm is not doing enough. It can be improved to match more levels as identical. (like it can remove deadend tunnels, areas where boxes can never be pushed to, and the player is not using it as part of solving the puzzle, they can all be turned into walls -- these can be all calculated as part of the normalization process.)

I am not sure why it's so hard to convince WayneCa that some levels are identical. YES, even Thinking Rabbit know that they are the same. They just want to reuse the same level in different games so that they don't have to design new levels. It should be very very easy to see.

Imagine this:

You copy a level down onto paper (or print out a level on paper).
Now, rotate the paper 90 degrees.
Does the level change? Absolutely not, it's still 100% the same level.
The level is 100% identical.
If you print the level on transparency paper (like back in the old day with overhead projectors), then you can easily see the same level can be viewed
rotated 90, 180, 270 degrees. Flip the paper and then do the same.
It's easy to see why we consider one level has 8 identical views.
The level itself was never changed. We can also apply the same transformation to the solution to get the solution for each of the 8 views of the same level. If you use YSokoban, you can rotate the level in any of the 8 views, the solutions will be automatically rotated, you don't have to do anything.
There are also tools out there to rotate level and solution for you.
So, just let go of the idea about identical level comparison.
THEY ARE 100% THE SAME LEVEL!!!!

Now, back to the point you're unhappy about.
I also always like to have all levels in the set, I never care about the same level appeared in 100 different other sets because I know I don't have to solve them more than once. Not sure whether Sokoban for Windows has this capability, I use YSokoban and it will automatically tell me that a level has been solved -- even when that level is solved in other sets. As such, I just skip all levels I already solved and only look at those levels I have not solved. If I want to get a set of all UNIQUE levels in my entire collection, it's very easy to do. Run the SOKODUP tool and it can give you only unique levels.

As looking for the complete sets for Perfect and Revenge, you may be able to find them somewhere on the internet. I know there are sites that has them and even with screenshots. Cannot remember the name of the site off hand, but I know it's out there. The two sets in question used to be available on Yahoo's Sokoban Group's file section as well. You can check it out.
If all means fail, you can always go thru every single level in Perfect or Revenge and then do screen capture and manually convert them to XSB or use a tool like Riddle Sokoban or YASC to convert from Image to XSB.
You know how sometimes a level appears to be different than what's in the game.
This way, you also have the screenshots to prove that the levels are correct.

I was going to create a different thread for this, but since ben has offered his opinions, I will do this here. A large part of what I do (because I like to and want to, not because I have to) is compare levels when they are similar. I like to document what I find. I like to think that my documenting style is unique. Others may disagree.

Below is the file I created comparing Boxxle1 and Boxxle 2 to Original.txt and to the originals as I have them in my Tribute file. Since I downloaded the Boxxle 1 & 2 files from this site, I can only think that the algorithm was bypassed or is not as capable as it is supposed to be.

Of the 30 levels found similar, 16 of them are merely flipped vertically in both of the Boxxle sets and 1 is rotated 90 degrees clockwise in the Boxxle 2 set with no other alterations at all. There are 4 more that are identical to the original ms-dos/color computer/apple 2/commodore 64 variants and only differ from the xsokoban variant. All 4 occur in the Boxxle 1 set and are only flipped vertically with no other alterations.

The rest have been modified, mostly in a slight way (change of start position, addition or removal of a wall block or box/target, although a few have additional column or row area. The last puzzle is included as it appears to me to be a highly remodeled variant of original puzzle 8.

The file is not intended to be played. It is for comparison of the levels. The file is in YAsC's sok file format and includes notes both at the beginning of the file and with each puzzle included.

It is my hope to be able to perform the same type of comparisons to perfect and revenge if I can find them in complete form. Thank you ben for your comments as I now have other places to search.

When I want to look for duplicates, I use SOKODUP.
It's easy to find duplicate levels and it generates a very nice report show whether levels are identical (levels are the same in any of the 8 possible views and that there is clear path between the levels' player starting positions). It also tells you if levels are the same but player's position different and there's no clear path to get from one to the other without doing any push.

Any time you have to alter the orientation of a puzzle you are changing it. Again, up is NOT down, left is NOT right. To get a grasp of what I am saying, try pasting the solution to Original #1 to a vertically flipped copy of that puzzle. Every Sokoban engine I know of will tell you that the solution is not valid for that puzzle.

Actually there is. Ysokoban can do that for all 8 orientations, including the situation if only the position of the man has been altered. 8 level transformations and changing the player position to the "valid"/compatible position is considered to be the same level and thus a duplicate.

What I do want is a copy of Perfect and a copy of Revenge with all 306 levels in each set. Can anyone here point me to links for such copies?

Uploaded them for you and anyone who is interested. Also these txt files are available on the internet in complete (306) form. But there was a time, when they were soled for money by the authors.

http://www.bwass.org/bucket/Perfect%20(306)%20levels.txt

http://www.bwass.org/bucket/Revenge%20(306)%20levels.txt

The general oppinion on duplicates is this: we can not disturb the composition of the released level sets, even if that means keeping the duplicates. We all know that these collection have 306 levels each. Removing duplicates would disturb the original composition of the collection, which the authors had in mind. But of course this general rule is broken if the purpose of any site is to not host duplicates. These collections are then considered to be unique and subjective.

Thank you, Mark. I have been looking all over the net without finding them. I found one called Perfect for the ZX computer that was actually the original 50 and not Perfect.

I found a site where I could play Boxxle 1 and 2, and to my surprise I found that the first 8 levels of Boxxle 1 are flipped vertically from the copy I downloaded from here. All 8 of them. I have not checked the others yet, but I am beginning to think that whoever made these text file versions rotated all of them. If that's the case, then my comparisons are null and void because all of the ones I determined to be flipped vertically are not. I will be checking all 108 Boxxle 1 puzzles and all 120 Boxxle 2 puzzles against the ones on that site.

It appears Francais mirrored those levels vertically from the official boxxle collections. So the collection on the Sokobanonline is again been edited/adopted. Attached are the "correct" boxxle collections.